Calorimetric bomb.



G. FERY. GALORIMETRIG BOMB. APPLIOATIOK FILED we. 17, 1912.

Patented July 22, 1913.

IIIIIIIIIIIIIIIIIIIIIIIIIIIIIII INVENTOR: M jyfltaor'me ya, 5' ji gWITNESSES.- 0% M. M

UNITED CHARLES FERY, or" rams, FRANCE.

CALOBIMETRIC BOMB.

Specification of Letters Patent. Patented July 22, 1913.

Application filed August 17, 1912. Serial No. 715,642.

To all whom it may concern: Be it known that 1, CHARLES Ffinr, a citizenof the Republic of France, residing in ParisyFrance have inventedcertain new and useful Improvements in or Relating to CalorimetricBombs, of which the following is a specification.

The object of this invention is to provide an apparatus capable ofrapidly measuring the calorific power of solid, liquid or gaseous fuelsor combustibles such as coal, petroleums, industrial gases and the like.

The apparatus constitutes an improvement on the calorimetrie bombs ofBerthelot and of Mahler. In these known apparatus, the fuel orcombustible is inclosed in a very thick vessel of platinated or enameledsteel into which oxygen can be compressed. The bomb itself is immersedin a calorimeter full of water, and the rise of temperature (which owingto the great calorific mass of the system is very slight) measures therequired calorific power. The experiment takes some time andnecessitates the employment of thermometers reading to 1/100 of adegree; moreover the results obtained have to be corrected for thecooling that takes place during the measuring operation itself. Theapparatus of the present invention avoids these various drawbacks. Asshown by the drawing which is a section through the apparatus, this iscomposed of a steel cylinder A in which the fuel or combustible isignited in compressed oxygen (admitted at 0) as with the oldcalorimetric bombs by the electric incandescence of a fine iron wire fthrough which a current can be sent from outside. This iron wire thecombustion of which produces only a negligible quantity of heatrelatively to that evolved by the combustion of the coal or substance tobe tested and placed in the cupel G, can be raised to incandescence bysending a current through it by the rods a and b which are insulatedelectrically from the metal of the bomb A. This latter is supportedaxially of an outer cylinder D of brass by two plates K of eonstantan orany other metal of high thermoelectric power. Constantan is an alloy ofequal parts of nickel and copper. The bomb A therefore forms the hotjunction of a thermo-electric couple, the cold junction of which is'formed by the outer brass casing D.

To measure the difference of potential attained on heating the bomb bythe combustion of the fuel, the bomb is connected to a volt-meter H bythe terminal E soldered to thebomb and by the terminal F insulated fromthe casing D. The casing D is connected direct by the terminal G to theother terminal of the measuring instrument. Owing .to the'small mass ofthe bomb, which can weigh even less than 1 kilogram instead of 3 1/2kilograms like the bombs of the old apparatus, and above all owing tothe doing away with the large mass of water (2 kilogr. 200) which in theknown apparatus is interposed between the bomb and the measuringinstrument (thermometer reading to 1/100 of a degree), the indication ofthe measuring instrument or apparatus (voltmeter or any other device formeasuring electrical energy) is very rapid with the present invention,thus dispensing with the necessity for any correction as practised withtheknown apparatus. Moreover with the old apparatus the product of thespecific heat into the mass of the bodies employed is very large:

Bomb 3 kg. 500x01: 350 calories Water 2 kg. 200 1:2200

Total "2550 With the apparatus of the present invention we only have asthe product of the mass of the bomb into its specific heat:

It follows that for an equal quantity of heat evolved per gram ofcombustible, the rise of temperature to be measured will be inverselyproportional to the calorific masses, i. e. the product P. C of theweight P into the specific heat C.

In existing calorimetric bombs a rise of 2 to 3 is obtained whichnecessitates the employment of thermometers reading to at least 1/50 ofa degree to secure an accuracy of one per cent. The new apparatus willallow of obtaining a rise of temperature 25 to 30 times as great, sayabout 70 C. The eonstantan couple gives about 0 millivolt 04 per degree.The voltage obtained will therefore be 2 millivolts 8. Now it ispossible to procure millivoltmeters with a pointer moving over a dialand giving a of the voltmeter are proportional to the temperatureattained and consequently to the required calorific power, if the sameweigh '1 of the substance to be measured (for examnle 1 gram) is alwaystaken. In order to calibrate the apparatus, therefore, it will only benecessary to measure carefully the deflection given by the combustionof'one gram of a well defined substance which can be readily obtainedchemically pure. Pure carbon produced by the calcination of sugar ornaphthalene are in this category. We

' will take 9690 calories as the calorific value of the lattersubstance. It will then sulfice to divide into 969 parts the lengthbetween the zero of the dial and the point obtained in the calibration,so that each division will represent 10 calories. v Th heat ofcombustion of industrial coals being between 7000 and 8500 calories, anerror of one division will therefore only give an errer of 1/800: 0.12per cent., a degreeof accuracy which is more than suflicient forpractical requirements. This invention therefore provides an industrialcalorimeter capable of giving at once by direct reading and withoutcalculation, the calorific power of solid, liquid and even gaseouscombustibles. of gaseous combustibles a given volume of the gas mixedwith an excess of oxygen will be compressed into the bomb. This resultis obtained by the dispensing with the water employed around the bombwith the old calorimetric bomb apparatus and by measuring thetemperature of the bomb by a thermo electric method which atonce givesthe temperature of the metal at the point of contact without the heathaving to pass through the water, which is a bad conductor of heat andrequires to be constantly agit-ated throughout the. duration of themeasuring or testing operation which occupies about 10 minutes.

Claims:

1 A calorimetric bomb comprising a steel cylinder in which a combustibleis adapted to be ignited in compressed oxygen, an outer brass cylinder,a fine iron wire adapted to be heated to ignite said combustible, meansfor supporting said cylinder axially of the said outer cylinder of brasswithout inter position of a mass of water, said means comprising partsof high thermo electric power, the arrangement being such that the bombforms the hot junction of a thermo-electric In the case couple the coldjunction of which is formed by the outer brass casing.

2. A calorimetric bomb comprising a steel cylinder in which acombustible is adapted to be ignited in compressed oxygen, an outerbrass cylinder, a fine iron wire adapted to be heated to ignite saidcombustible, means for supporting said cylinder axially of the saidouter cylinder of brass without interposition of a mass of water, saidmeans comprising parts of high thermo electric power, the arrangementbeing such that the bomb forms the hot junction of .a thermo-electriccouple the cold junction of which is formed by the outer brass casing,and an apparatus for measuring electric energy, graduated in calories,and the terminals of which are 'connected to the thermo-electricelementformed by the system composed of the bomb and outer cylinder. i

3. A calorimetric bomb comprising a 'container, a metallic envelopsurrounding said container, said container having substantially solidwalls, and an interposed portion composed of a body of appreciablethermoelectric power communicating directly with said container andenvelop without the interposition of a mass of water, in which thecontainer forms the hot junction and the envelop 'the cold junction of athermo-electric couple, the value of the electro-motive force developedbeing the measure of the calorific power.

4. A calorimetric bomb comprising a cylinder, a casing, and anintervening part of a material of an appreciablethermo electric power,whereby the cylinder and intervening material form the hot junction andthe intervening material and casing form the cold junction of a thermoelectric couple, the value of the electromotive force generated by whichis a measure of the calorific value of the combustible.

5. A calorimetric bomb comprising a cylinder, a casing, and anintervening support of a material of an appreciable thermo electricpower, whereby the cylinder and vintervening material form the hotjunction and the intervening material and casing form the cold junctionof a thermo electric couple, the value of the elect-romotive forcegenerated by which is a measure of the calorific value of thecombustible.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

H; C. Ooxn,

RENE: BARDY.

